. Author manuscript; available in PMC: 2009 May 1.

Published in final edited form as: Am J Speech Lang Pathol. 2008 May;17(2):121–138. doi: 10.1044/1058-0360(2008/013)

Table 6.

Results of linear and quadratic regression analyses for MBCDI subscales from chronologic Test Age 4.5

		Step 1 – Linear Regression				Step 2 – Quadratic Regression
Test/Subscale	Parameter	Regression Coefficient (β)	Standard Error	Semi-Partial r²	Step Increment in R²	Regression Coefficient (β)	Standard Error	Semi-Partial r²	Step Increment in R²
MBCDI Vocabulary RS					.441				.001
	Intercept	1183.699	94.994			1138.906	168.593
	Pre-CI Aided	-5.378^***	1.029	.215		-.401^***	1.038	.215
	Age at CI	-13.614^***	1.960	.379		-9.351	13.363	.004
	(Age at CI)²	-	-	-	-	-.088	.273	.001
MBCDI Irregular Words RS					.372				.004
	Intercept	44.290	5.160			49.383	9.135
	Pre-CI Aided	-.252^***	.056	.180		.249^***	.056	.175
	Age at CI	-.642^***	.106	.321		-1.126	.724	.022
	(Age at CI)²	-	-	-		.010	.015	.004
MBCDI Sentence Complexity RS					.479				.001
	Intercept	78.834	7.417			82.598	13.162
	Pre-CI Aided	-.429^***	.080	.209		-.426^***	.081	.205
	Age at CI	-1.170^***	.153	.429		-1.529	1.043	.016
	(Age at CI)²	-	-	-	-	.007	.021	.001
MBCDI 3 Longest Sentences RS					.178				<.001
	Intercept	19.051	3.423			19.215	6.08
	Pre-CI Aided	-.084^*	.037	.060		-.084^*	.037	.059
	Age at CI	-.269^***	.071	.169		-.285	.482	.004
	(Age at CI)²	-	-	-	-	.000	.010	<.001

^***

p ≤ .001

^**

p ≤ .01

p ≤ .05

Note: Squared semi-partial correlations can sum to greater than the squared multiple correlation under conditions of suppression. This occurs when the effect of a predictor is suppressed by another predictor and is only revealed when the other predictor is partialled. CI = Cochlear Implant, RS = Raw Score